Madrid: World number one Novak Djokovic racked up his 30th win of a dominant season with a 6-2, 6-1 destruction of Spain's Roberto Bautista Agut to reach the Madrid Masters quarter-finals on Thursday.

The resurgent Rafael Nadal and defending champion Andy Murray also remained on course for a semi-final clash as they eased past Sam Querrey and Gilles Simon respectively in straight sets.

Djokovic is playing in Madrid for the first time in three years, but hasn't taken long to adjust to the different conditions in the altitude of the Spanish capital as he has reached the quarters for the loss of just nine games.

Novak Djokovic returns a ball at the Madrid Open. AFP

"After a long game at 2-2 in the first set, I managed to break his serve. It was a flawless performance after that, everything worked very well," said Djokovic.

"Today the way I played gives me a lot of satisfaction. I'm just hoping I can continue playing this well tomorrow."

The Serb will continue his quest for a fifth title of the season against Milos Raonic as the big serving Canadian dumped out seventh seed Jo-Wilfried Tsonga 6-4, 6-4.

Nadal stretched his perfect start to the European clay-court season to 12 matches as he fought back from going down an early break to beat Querrey 6-4, 6-2.

The 14-time Grand Slam champion is in fine form after victories in Monte Carlo and Barcelona and is seeking to break Guillermo Vilas' record with a 50th clay-court title in Sunday's final.

Nadal started slowly as Querrey stormed into a 3-0 lead and had a break point to lead 5-2.

However, Nadal turned the match around by winning six straight games to seal the first set and break early in the second.

Querrey broke back to level at 2-2, but Nadal pulled away in the final stages to remain on course for a fifth title in Madrid.

"I had the confidence that if I managed to make the rallies longer, more than three balls, I knew that things could turn around," said Nadal.

"Luckily that's what happened. I saved that important point when we were at 4-2. Then from 4-2 I managed to break him and from there on things went more or less perfectly."

In the women's Madrid Open, the only remaining seed Simona Halep was victorious in an all-Romanian quarter-final against Irina-Camelia Begu 6-3, 0-6, 6-1.

Halep -- a finalist in Madrid in 2014 - will face former US Open champion Sam Stosur after she beat Patricia Maria Tig 6-3, 6-4.

American qualifier Louisa Chirico also continued her fairytale run to reach the semi-finals.

Chirico, ranked 130 in the world, beat Australian Daria Gavrilova 7-6 (7/1), 6-2 to reach her first ever WTA semi-final where she will face Dominika Cibulkova, who came from a set down to beat the fourth Romanian in the quarters, Sorana Cirstea, 4-6, 6-3, 6-3.